In a wireless broadcast and multicast system, radio link quality of MSs varies significantly with MS location, and channel conditions between some MSs and BSs are relatively desirable, while others are very poor. In order to consider receiving capabilities of most of the terminals that need to receive broadcast and multicast information in a cell, the BS generally needs to select an encoding rate with a service quality acceptable to the terminals in the cell which exhibit poorer channel quality, and then transmit information to all terminals in the cell at the selected encoding rate.
In the current broadcast and multicast information technologies, a first MS may have a high probability to correctly receive signals with a high encoding rate since the first MS is close to the BS and the channel condition is desirable, while a second MS has a low probability to correctly decode the signals with the high encoding rate since the second MS is far away from the BS and the channel condition is poor. When the BS transmits the broadcast and multicast information, in order to enable the first MS and the second MS to both correctly decode the received signals, the BS can only transmit the information at an encoding rate that can be accepted by the second MS.
In the implementation of the present invention, the inventor finds that the prior art has at least the following problems. Since the BS transmits the information at a relatively low encoding rate, all the MSs that need to receive the broadcast and multicast information should maintain a radio frequency receiving state at all times until the transmission of the broadcast and multicast information to be received is completed. Therefore, not only is the power consumption of the MSs increased, but the broadcast and multicast information received by MSs close to the BS with desirable channel conditions have a large number of redundancies. Under such circumstances, the receiving efficiency is low.